Answer:
graduated cylinder
Explanation:
It shows exact volume very precisely.
Answer:
obsidian
Explanation:
because it is an igneous rock which is smooth
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
No of protons=107+1=108
No. Of neutrons=158
Mass no. =166
<h3>Answer:</h3>
Number of Protons = 9
Number of Neutrons = 9
Number of Electrons = 10
<h3>Explanation:</h3>
Number of Protons:
The number of protons present in any atom are equal to the atomic number of that particular atom. Hence, as the atomic number of Fluorine is 9 therefore, it contains 9 protons.
Number Neutrons:
The number of neutrons present in atom are calculated as,
# of Neutrons = Atomic Mass - # of protons
As given,
Atomic Mass = 18
# of Protons = 9
So,
# of Neutrons = 18 - 9
# of Neutrons = 9
Number of Electrons:
As we know for a neutral atom the number of electrons are exactly equal to the number of protons present in its nucleus. So, for 9 protons in neutral Fluorine atom there must be 9 electrons. But, we are given with Fluoride Ion (i.e. F⁻) so it contains one extra electron hence, it contains the total of 10 electrons respectively.
